Mitchell’s HardoRapid is a quick setting hydraulic cement which instantly stops gushing water or seepage through concrete or masonry structures. When mixed with fresh water, it causes rapid setting within 1 to 2 minutes and is therefore ideally suited for plugging and stopping infiltration of water through concrete or brickwork. The setting time will depend on the site conditions, weather and temperature of mixing water, higher temperatures will accelerate the setting while some retardation may occur at lower temperatures.


HardoRapid is primarily used for emergency and immediate water shut off from holes, cracks and fissures or from any other spot where the water leakage is heavy enough to impede the proper application of waterproofing system. HardoRapid has been specifically designed for stopping gushing water, it is not a general waterproofer or vapour barrier. Once the inflow of water has been stopped with HardoRapid, the permanent waterproofing of the structure should be carried out with a suitable waterproofing product such as Mitchell’s FERROSEAL or Mitchflex 2 K.


  • Quick setting
  • Resists high water Pressure
  • Easy to apply
  • Economical


  • For all preliminary waterproofing work on very wet surfaces.
  • For plugging holes and cracks in water tanks prior to the application of waterproofing coating.
  • For sealing and plugging high pressure water leaks in basements, underground structures, concrete pipes and ducts etc.


The area to be plugged with HardoRapid should be cleaned as much as possible. All loose material and unsound concrete should be removed. At the point of water penetration, the surface should be cut and a dovetail or rectangular type hole be formed, deep and wide enough to allow for proper plugging. A deeper cut will result in better plugging and sealing.
In a dry container pour sufficient quantity of water and then add HardoRapid to form a thick paste, keep stirring the mix till the required consistency is achieved. HardoRapid starts to set as soon as it is mixed, wait for a few seconds to let it harden enough and then with a gloved hand mould this paste into the form of a cone shaped plug and force this plug into the prepared hole. Hold the plug in place applying pressure of your thumb or palm till it has set firmly sealing and cutting off the water penetration. Depending on the pressure of water and weather conditions, it will take 1 to 2 minutes before HardoRapid is firmly set in place and the hand pressure can then be released.


1, 5 and 25 Kg Bags


For further details and assistance for specific application requirements and for other product information please contcat Mitchell at the addresses given below.